The present embodiments relate to a method and a device for irradiation treatment planning.
Prior to radiotherapy, an irradiation treatment plan is determined. This determination is sometimes difficult, since the internal anatomy of a patient may change over time. For example, target volumes inside the abdomen may change location from day to day or over the course of several days or weeks. A typical organ that is often subject to a change of position is the prostate. For example, the bladder, situated next to the prostate, and the rectum, situated next to the prostate, may exert an influence on the position and shape of the prostate depending upon the degree of filling of the bladder and/or the rectum.
One possibility of taking account of these changes is the use of safety margins. During irradiation treatment planning, safety margins are selected such that an internal displacement/deformation of the target volume is taken into account. Although the safety margins may moderate the adverse effects of a change of position of the target volume, the safety margins may lead to irradiation of adjacent, critical structures, such as the bladder or the rectum, for example.
A concept is known from US 2005/0201516 A1, with which a plurality of irradiation treatment plans with different safety margins (multiple-margin optimization with daily selection (MMODS)) may be calculated for a target volume. A user may choose in real time from a plurality of optimized irradiation treatment plans with different safety margins in order to take account of an observed change in the size or position of the tumor or the structures surrounding the tumor.
US 2010/0088339 A1 discloses a method, with which the most suitable irradiation treatment plan is selected from a plurality of previously established irradiation treatment plans prior to an irradiation fraction.